Jessica Sanchez weighs 96 pounds and stands just five-foot-one, but she appeared larger than life Thursday night when she took the spotlight during the “American Idol Live! 2012” tour at Valley View Casino Center.

The 16-year-old Chula Vista singing sensation also sounded larger than life, thanks to her rich, full-bodied voice and ability to phrase and project with a degree of poise and power rarely heard in someone so young or diminutive.

That’s the good news, although it’s hardly news to anyone who watched as Jessica rose higher and higher on “American Idol” this year, only to come in second to Phillip Phillips on the season finale. While that finish was predictable, given “Idol’s” history in recent years of viewers giving the most votes to the WGWG candidate (short for White Guys With Guitars), it came as a surprise to Phillips himself.

“I didn’t think I was going to win. I’m not that good a singer,” Phillips said Thursday afternoon during a backstage interview at Valley View Casino Center. “I would have been happy to come in 20th.”

The bad news, at least for those fans eager to hear Jessica soar at length, is that she only had three featured numbers during the concert. And while she turned in the most mature and assured solo segment of the night, it was disappointing that she wasn’t afforded the opportunity to stretch out.

Of course, the “Idol” formula has always been to compress and truncate songs, the better to – hmm – who knows exactly? Cater to viewers with Attention Deficit Disorder? Minimize the squirming when marginal vocalists are featured, as was the case with at least half of Thursday night’s concert?

Whatever the reason, Jessica had all of 11 minutes for her three songs, which opened the show’s second half. Her selections included the Beyonce hit, “Best Thing I Never Had,” Prince’s “How Come U Don’t Call Me Anymore?” and the rollicking Ike & Tina Turner version of Creedence Clearwater Revival’s “Proud Mary.”

Being back in San Diego gave her performance an added air of excitement – an air she could barely contain during a separate backstage interview Thursday.

“It’s amazing,” said Jessica, whose debut album is due out in November on Interscope records. “This is the place where I saw my first concert – Christina Aguilera – when I was 12. Every time I went to a concert (here) I dreamed of singing on that stage. And now I’m able to do that in my hometown. It’s insane!”

Jessica delivered on all three of the songs on which she was spotlighted, and when she ignited the audience ignited with her. She was so good on her sultry, slowed-down version “How Come” (which found her singing with bluesy fervor and stunning, gospel-inspired flourishes), that one suspects even the notoriously hard-to-please Prince would be delighted at the result.

Intriguingly, while Jessica was eager to cover Prince on “Idol” this season, she never did. Apparently, the show’s producers deemed Prince’s asking price for broadcast rights to any of his songs be too steep. Considering just how potent her Etta James-inspired performance of “How Come” was Thursday, “Idol” would have done well to pony up the money.

(As for Prince, one suspects his asking price is so high specifically to limit the possibility of inferior performances and because he probably never imagined that any “Idol” singer could elevate any of his songs the way Jessica did.)

Jessica also soared Thursday on “Proud Mary,’ despite its abbreviated length. She received lively vocal support on the Credeence classic from third-place “Idol” finisher Joshua Ledet and from runner-up DeAndre Brackensick, who – Jessica tweeted last week – has recently become her boyfriend. All three danced with verve, vigor and infectious enthusiasm.

Jessica, who was criticized by "Idol" judge Randy Jackson for not moving enough during some of her performances on the show, had no problem working – and commanding – the enormous stage Thursday. Like the evening's nine other performers, she benefited from the polished accompaniment of the tour's five-man backing band.

Jessica also performed ably when she and Brackensick accompanied the amiable but tuneless Heejun Haan on LMFAO’s “Party Rock,” a selection that gave her a rare opportunity to rap, however briefly. And she simmered very nicely on her duet with Phillips on the moody Damien Rice ballad “Volcano.”

But considering the wince-inducing turns by Haan, Erika Van Pelt, Elise Testone (who mangled Zeppelin’s “Whole Lotta Love”), Skylar Laine (who did the same with The Faces’ “Stay With Me”) and Colton Dixon (who was so flat and off-key he might consider selling clam franchises), it’s a mystery why Jessica wasn’t featured more – and, by extension, some of the other “Idol” finalists less. Then again, for most of Thursday’s performers, this tour is likely the culmination of their short-lived musical careers, not the start.

As for Phillips, he has an engaging personality, a winning smile and the ability to make almost anything he performs – including, on Thursday, Usher’s “Nice and Slow” and Gotye’s “Somebody That I Used to Know” – sound like it is being sung by Dave Matthews, his biggest artistic inspiration. The challenge for Phillips, whose debut album is also scheduled for this fall, will be to sound like, well, himself. He may also want to work on his elocution; most of his between-song comments were muffled and difficult to discern.

Considering that Phillips is writing or co-writing all the songs on his upcoming album, it was surprising that he didn’t preview a single one of them Thursday. This held especially true since Dixon was allowed to do one of his own original songs, the generic power-ballad “Never Gone.” (Dixon also delivered a ham-fisted rendition of Switchfoot’s “Mean To Live,” about the less said, the better.)

Ledet accounted for one of the night’s highlights with his charged version of James Brown’s “It’s a Man’s Man’s Man’s World.” He and Sanchez delivered a terrific version of the Aretha Franklin/George Michael hit “I Knew You Were Waiting for Me.” It was the only time “Idol’s” two most gifted singers from this season did a duet Thursday. They should have done another.